Method of forming sprags for one-way clutches



Aug. 16, 1955 T. SZADY METHOD OF FORMING SPRAGS FOR ONE-WAY CLUTCHESFiled Feb. 5, 1951 F|G.2. A FlG.l.

F|G.4. I

M E/L E l I INVENTOR.

LEOPOLD T.SZADY BY m W ATTORNEYS United States Patent METHOD OF FEBRMINGSPRAGS FQR ONE-WAY CLUTCHES Leopold T. Szady, Detroit, Mich assignor toFormsprng Company, Van Dyke, Mich a corporation of Michigan ApplicationFebruary 5, 1951, Serial No. 209,356

3 Claims. (Ci. 29-414) The invention relates to the method of makingoneway clutches including coaxial driving and driven rotary membershaving radially spaced concentric raceways thereon, and a series ofsprags interposed between said raceways. With such constructions it isnecessary to provide means for energizing the sprags or turning them soas to frictionally engage the raceways. This is som times accomplishedby garter springs surrounding the series of sprags and engaging properlyinclined notches or apertures therein, so as to impart to each sprag atorque stress. With certain constructions garter spring receivingnotches are formed in one or both ends of the sprag usually subsequentto the severing of the sprags from a stock bar and the heat treatmentfor hardening the same. However, this requires not only a distinctmechanical operation but also the orienting of the separate sprags forfeeding to the notch forming means.

It is the object of the instant invention to obtain a construction ofsprag in which the spring receiving notches may be made in the stock barprior to the severing of the sprags therefrom.

To this end the invention consists in the constructio of the sprag andthe method of forming the same as here inafter set forth.

In the drawings:

Fig. 1 is a side elevation of a sprag of my improved construction;

Fig. 2 is an end elevation thereof;

Fig. 3 is a plan view illustrating a method of forming the notches inthe stock bar and then severing the bar into individual sprags;

Fig. 4 is a view similar to Fig. 3 illustrating a me ified method forforming the notches in the stock bear and for severing the same intoindividual sprags;

Fig. 5 is a side elevation of the construction of sprag illustrated inFig. 4; and

Fig. 6 is an end elevation thereof.

My improved sprag may be varied as to its cross sectional contour but,as specifically illustrated, this contour includes diametricallyopposite eccentric cam p0r tions A and B, a generally radial side Cbetween said cam portions and an opposite side having oppositely i"-clined portions D and E extending to a central rounded nose portion F.The sprags may be formed from drawn or extruded stock bars having thecross sectional contour as just described and such bars are severed intosuitable lengths for forming the individual sprags. However, before theseverance of the sprags the bar is notched and the notches are locatedto be at one or both ends of the severed sprags. The notches G extendtransversely across the sprag adjacent to one of the cam surfacesthereof and are inclined from the side C to the side portion E. Thuswith a series of sprags in assembled relation to the other elements ofthe clutch, a garter spring can be engaged with the notch of the spragand will bear thereagainst at one side of the center of turning of thesprag so as to impart a torque stress thereto. This will energize thesprags to turn the cam faces A and B thereof into fric- 2,715,262Federated Aug. 16, 1955 tional engagement with the raceways on thedriving and driven members. To retain the garter spring when onceengaged, the notches G are undercut as indicated at H so that theresilient pressure of the spring against such undercut portion will holdit from endwise displacement.

In the method of forming the sprags, as above described. the stock bar Iis advanced longitudinally step by step a distance equal to the lengthof the sprag plus the material removed in the severing of the bar. Thenotches G with their undercut portions H are formed by moving a suitablefashioned rotary cutter I transversely across the bar and through a pathto give the proper inclination to the notch. The cross section of thecutter J corresponds in contour to the undercut portion H of the notch.The bar is severed into sprag lengths by a rotary cutter K and ifdesired this may be coaxial with the cutter I but projects beyond theperiphery of the latter to extend completely across the bar. It will, ofcourse, be understood that Where both operations are performedsimultaneously by cutters J and K on the same arbor it will be necessaryto hold the bar from transverse displacement during this operation.

Sprags formed by the method above described only require heat treatmentand hardening to complete the same and are then in condition forassembly in the clutch.

With the modified method illustrated in Fig. 4, a rotary cutter orgrinder Wheel L is fashioned to form the notches in the bar and thissame cutter is used for severing the bar into individual sprags. Inalternate operations of the cutter L, it is moved iaterally differentdistances With respect to the bar M and intermediate each operation saidbar is advanced an amount substantially equal to onehalf the spraglength. Thus in one operation of the cutter L, it is moved to form anotch in the sprag and in the alternate operation it is moved completelyacross the bar to sever the sprag therefrom. As the advancement of thebar is between each operation of the cutter, the notch will be locatedcentrally between the ends of the severed sprag.

What I claim as my invention is:

l. The method of forming sprags for one-Way clutches comprising forminga stock bar having a cross sectional contour including diametricallyopposite eccentric cam portions, cutting successive spaced transversechannels through one of said cam portions while integral with said stockbar and severing the bar into sprag lengths, each including at least oneof said channels.

2. The method as in claim 1 in which spaced pairs of adjacent channelsare cut through said cam face the channels of each pair being fashionedto increase in depth in directions away from each other, and severingthe bar between adjacent channels of each pair to form in the severedsprags undercut channels opening through opposite ends thereof.

3. The method as in claim 1 in which the forming of the channels and thesevering of the sprags is performed by the same cutter in alternateoperations thereof the severing operation being of greater depth.

References Cited in the file of this patent UNITED STATES PATENTS2,100,619 Wenn Nov. 30, 1937 2,156,692 Hixon May 2, 1939 2,165,454Cornell, Jr. July 11, 1939 2,213,040 Drissner Aug. 27, 1940 2,282,537Whitney May 12, 1942 2,459,568 Lyon Ian. 18, 1949 2,486,603 King, Jr.Nov. 1, 1949 2,542,914 Farkas et a1 Feb. 20, 1951 2,557,773 Steinman uJune 19, 1951

